The present invention relates generally to systems for balancing wheel-tire assemblies and more specifically relates to a balancing system wherein movable mass elements are positioned loosely within the tire portion of a wheel-tire assembly and means are provided for inhibiting movement of the mass elements after they have been distributed by rotation of the tire into balancing positions.
Numerous means have been provided through the years for properly balancing wheel-tire assemblies so that the tire does not wear unevenly thereby extending the life of the tread on the tire. Probably the most commonly employed system for balancing wheel-tire assemblies is to fixably secure lead weights or the like to the rim of the wheel at a position which is substantially diametrically opposed to the mass of the wheel-tire assembly which tends to cause an imbalance in the assembly. Such systems, however, are not entirely satisfactory since the weights are fixed in position and thereby remain in position when the wheel-tire assembly loses its balanced condition for any one of numerous reasons, such as the wheel becoming out of line or the tires receiving gouges or the like.
Systems have been employed for positioning moveable mass means in a wheel-tire assembly with the mass means, upon rotation of the wheel and tire assembly, seeking a position which is diametrically opposite the mass of the assembly which tends to cause an imbalanced condition. Such systems typically employ a closed but hollow ring fixably secured to the wheel with the moveable mass means being positioned within the ring. Such systems are not entirely satisfactory since the mass means which are confined within the closed ring, while balancing centripedal forces about the axis of rotation, do not compensate for lateral imbalance of the assembly.
Similarly, systems have been developed which do compensate for lateral imbalance by placing mobile mass means loosely within the tire so that the mass means not only distribute themselves circumferentially within the tire to balance centripedal forces, but also distribute themselves laterally of the tire to balance lateral forces. An example of such a system is disclosed in U.S. Pat. No. 2,909,389 issued to J. C. Wilborn on Oct. 20, 1959. In this system, however, the mass means are in the form of spherical balls which readily seek a position within the assembly to balance the assembly, but also readily lose this position when angular speed of assembly decreases or increases.